1. Field of the Invention
The present invention relates generally to a messaging service, and in particular, to a system and method for providing a converged messaging service, which can be compatibly used with or replace various services, such as an Instant Messaging (IM) service, a Short Message Service (SMS), a Multimedia Message Service (MMS), a Voice over Internet Protocol (VoIP) service, and a Push To Talk (PTT) over Cellular (PoC) service.
2. Description of the Related Art
In general, messaging services include a Short Message Service (SMS) and a Multimedia Message Service (MMS) for transmitting and receiving a message between terminals, which do not support an Instant Messaging (IM) service, and the IM service and a Push To Talk (PTT) over Cellular (PoC) service for transmitting and receiving a message between terminals, which support the IM service.
A system for providing the SMS, which is a general one of the messaging services described above, is illustrated in FIG. 1. A process of transmitting and receiving a message between a terminal 110 and a Short Message (SM) server 100 in a system for providing the SMS will now be described with reference to FIG. 1.
A process of transmitting a message from the terminal 110 to the SM server 100 is described first. It is assumed that the terminal 110 is a sender's terminal for transmitting a message.
The terminal 110 creates a message to be transmitted and transmits the message to a Mobile service Switching Center (MSC) 106. In this case, the terminal 110 may transmit the message to a Serving General Packet Radio Service (GPRS) Support Node (SGSN) 106 instead of the MSC. If the size of the message to be transmitted exceeds a defined size, the terminal 110 divides the message having the large size into a plurality of messages having a small size and transmits the plurality of messages having the small size. When the MSC 106 receives the message from the terminal 110, the MSC 106 receives necessary information from a Visitor Location Register (VLR) 108, determines whether the received information has an error, and transmits the message to an SMS-Inter Working MSC (SMS-IWMSC) 102 if it is determined that the received information has no error. If the terminal 110 transmits the message to the SGSN 106, the SGSN 106 checks a Reply Path-Destination Address (RP-DA) parameter contained in the message, and if there is no error, the SGSN 106 transmits the message to the SMS-IWMSC 102. When the SMS-IWMSC 102 receives the message, the SMS-IWMSC 102 receives necessary information from a Home Location Register (HLR) 104 and transmits the message to the SM server 100.
A process of transmitting a message from the SM server 100 to the terminal 110 is described. In this case, it is assumed that the terminal 110 is a recipient's terminal for receiving a message.
When the SM server 100 receives an SM message from the sender's terminal as described above, the SM server 100 stores the SM message therein and transmits the SM message to an SMS-Gateway MSC (SMS-GMSC) 102. When the SMS-GMSC 102 receives the SM message, the SMS-GMSC 102 receives routing information from the HLR 104 and transmits the SM message to the corresponding MSC or SGSN 106. If the MSC 106 receives the SM message from the SMS-GMSC 102, the MSC 106 receives location information from the VLR 108 and transmits the SM message to the terminal 110. If the SGSN 106 receives the SM message from the SMS-GMSC 102, the SGSN 106 determines whether the SM message has an error, and if it is determined that the SM message has no error, the SGSN 106 transmits the SM message to the terminal 110.
As the SMS described above, another messaging service is performed according to a specific rule between a client and a server. That is, since a silo for each messaging service is constructed, in order to employ a plurality of messaging services, a configuration of a terminal may be complicated.
In terms of interworking between heterogeneous messaging services, interworking between the SMS and the MMS and interworking between the SMS and an Internet E-mail service have been being provided. However, for interworking between an Instant Messaging (IM) service and the SMS, a basic architecture and a network element function are described in the 3rd Generation Partnership Project (3GPP) standard, however, a detail process of processing an SMS message in order to transmit it as an IM message is not described. Thus, a new client for converging requirements to perform a plurality of messaging services and guaranteeing compatibility with existing messaging systems is required.
Meanwhile, in order to support a multimedia service in a mobile terminal and network, an Internet Protocol (IP) Multimedia Core Network (CN) Subsystem (IMS) function is defined in the 3GPP standard. An IMS network is a core of next generation mobile communication by providing core functions of IP multimedia communication, such as Session Initiation Protocol (SIP)-based session management, Quality of Service (QoS) management, interaction with a circuit network, and various additional services, such as security, charging, security and authentication, service profile management, user information storing, presence information and group information management. However, an IMS-based service is limited to an IM service based on PoC or SIP for IM and Presence Leveraging Extensions (SIMPLE). This is because a communication or messaging service based on IMS is still in an initial stage, i.e., a high-grade service based on IMS has not been developed. Thus, each messaging service can connect between only clients supporting the same messaging service. Technically, an existing user profile performs a proper service routing rule for only users having the same service characteristic.